Ten college women were divided into 5 groups and treated in randomized block design for 5 weeks with 1 interval between treatments and subjects serving as their own controls. The experimental diets were corn oil diet as a source of n-6 linoleic acid, perilla oil diet as a source of n-3 $alpha$-linolenic acid, and fish oil diet as a source of n-3 EPA and DHA. Dietary fat was supplied at 30% Cal and modified to give the total amount of saturated fatty acids and monoenoic acids at constant level. There was no significant effect on serum cholesterol level by different PUFA. However, on a gram-for-gram basis, there was a trend that the decrease in serum cholesterol was proportionate to the degree of fat unsaturation. On the other hand, only fish oil diet significantly decreased TG level but no significant effect on the relative proportion of TG in VLDL. The degree of hypotriglyceridemia did not corrleate with the degree of unsaturation. The relative proportion of CE in LDL was reduced by all PUFA diets but significant only by perilla oil diet. The relative amount of apoprotein in LDL was significantly reduced by n-3 PUFA. HDL-Chol content was significantly increased only in fish oil diet but no change in the relative proportion of its chemical components of HDL.